Nuget pack for multiple frameworks

Question

I am trying to make nuget package targeting multiple frameworks. But it doesn't work. csproj file:

<Project Sdk="Microsoft.NET.Sdk">
<PropertyGroup>
   <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
   <OutputType>Library</OutputType>
   <TargetFrameworks>net452;netstandard2.0</TargetFrameworks>
   <NuGetPackageImportStamp />
 </PropertyGroup>

running command:

C:\Repos\Random\TestStuff\.nuget\nuget pack "C:\Repos\Random\TestStuff\TestPackaging\TestPackaging.csproj"

It gives me error:

Error NU5012: Unable to find 'bin\Debug\TestPackaging\bin\Debug\'. Make sure the project has been built.

If I change config to:

<Project Sdk="Microsoft.NET.Sdk">
<PropertyGroup>
  <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
   <OutputType>Library</OutputType>
   <TargetFramework>netstandard2.0</TargetFramework>
   <NuGetPackageImportStamp />
 </PropertyGroup>
</Project>

everythings works fine. What am I missing? Changing location where I am running it from makes no difference.

EDIT: running command

C:\Repos\Random\TestStuff\.nuget\nuget pack "C:\Repos\Random\TestStuff\TestPackaging\TestPackaging.csproj" -build

gives different error:

Build succeeded.
0 Warning(s)
0 Error(s)

Time Elapsed 00:00:00.50
Packing files from 
'C:\Repos\Random\TestStuff\TestPackaging\bin\Debug\TestPackaging\bin\Debug'.
Could not find a part of the path 
'C:\Repos\Random\TestStuff\TestPackaging\bin\Debug\TestPackaging\bin\Debug'.

same with nuspec file

Answer 1

nuget.exe doesn't support packing PackageReference projects, and SDK projects are always PackageReference.

You should pack using either dotnet pack or msbuild -t:pack

Answer 2

To target Multiple frameworks with nupsec xml attributes in the csproj SDK style file. Add this TargetFrameworks(with an 's'), back in the csproj:

<TargetFrameworks>net462;netstandard2.0</TargetFrameworks>

Edit the manifest, add these lines in the ProjectGroup that defined TargetFrameworks:

<files>
  <file src="bin\Release\net462\TestPackaging.dll" target="lib\net452\TestPackaging.dll" />
  <file src="bin\Release\netstandard2.0\TestPackaging.dll" target="lib\netstandard2.0\TestPackaging.dll" />
</files>

Build the project, and the dll's go into their respective directories, the nuget get's built with source files for both target frameworks.